Photoenhanced electrochemical etching for p -GaN

An effective wet chemical etching method for p-GaN is proposed based on the surface band bending of the semiconductor. The metal organic chemical vapour deposition (MOCVD) grown p-GaN was successfully etched by biasing the substrate below –3 V during photoenhanced electrochemical etching using KOH solution and Hg lamp illumination. The etch rate increased with increasing negative voltage and was as high as 2.1 µm/min at –10 V.